展开 ((k+1)(2k^2+1))/2

解答

展开

\frac{( k + 1 ) ( 2 k ^{2} + 1 )}{2}

k^{3} + \frac{k}{2} + k^{2} + \frac{1}{2}

求解步骤

\frac{( k + 1 ) ( 2 k ^{2} + 1 )}{2}

乘开

(k + 1) (2 k^{2} + 1) : 2 k^{3} + k + 2 k^{2} + 1

= \frac{2 k ^{3} + k + 2 k ^{2} + 1}{2}

使用分式法则:

\frac{a \pm b}{c} = \frac{a}{c} \pm \frac{b}{c}

\frac{2 k ^{3} + k + 2 k ^{2} + 1}{2} = \frac{2 k ^{3}}{2} + \frac{k}{2} + \frac{2 k ^{2}}{2} + \frac{1}{2}

= \frac{2 k ^{3}}{2} + \frac{k}{2} + \frac{2 k ^{2}}{2} + \frac{1}{2}

数字相除:

\frac{2}{2} = 1

= k^{3} + \frac{k}{2} + k^{2} + \frac{1}{2}

e x p an d (a + b)^{2} + (c + d)^{2}

e x p an d \frac{4 ( x - 2 )}{3}

e x p an d P_{1} (6, - 2) y P_{2} (2, 4)

e x p an d \frac{2 ( 29 + 106 )}{3}

e x p an d d y (y = 5 x^{2} - 3 x + 2 \frac{1}{x - 1})